WASHINGTON — The Obama administration on Thursday imposed sanctions on three Islamic State leaders it said were crucial figures in sustaining the organization through oil revenue and the recruitment and deployment of foreign fighters. The move by the Treasury Department was the latest effort by the United States to choke off the terrorist group’s flow of cash and personnel.

The department said it was targeting Faysal al-Zahrani, a top oil official in Syria; Husayn Juaythini, who has worked with the group’s leader, Abu Bakr al-Baghdadi, to establish a foothold for the organization in Gaza; and Turki al-Binali, a recruiter and senior religious adviser for the Islamic State, also known as ISIS or ISIL.

The sanctions, which freeze any assets or property belonging to the men and bar Americans from having financial dealings with them, are intended to isolate the Islamic State from the world financial system by opening anyone who conducts business with them to penalties.

But the efforts to cut off the flow of the group’s vast wealth and steady flow of revenue face formidable obstacles, given that much of the money it collects is derived from its control of territory. Last year alone, the Treasury Department found, the Islamic State brought in $500 million from oil and gas sales. The American-led coalition battling the group has in recent months begun bombing Islamic State-held oil and gas fields and supply routes through an operation known as Tidal Wave II.

“Treasury and our partners worldwide are aggressively targeting ISIL’s ability to earn and make use of its money, and we are making progress on many fronts,” Adam J. Szubin, the top Treasury Department terrorism and financial intelligence official, said in a statement.

Mr. Szubin traveled last week to Turkey and France to speak with government officials and business executives about efforts to target the Islamic State’s finances. He has also been working to deprive the group of its ability to place and move money around the world, in part through pressing foreign governments to impose tighter regulations on banks and money exchanges. That effort will be a focus of a meeting on Sunday in Paris that will bring together officials from 37 countries and an international task force on terrorist financing to discuss ways of disrupting the group’s financial flows.

The Treasury Department said Mr. Zahrani served directly under Abu Sayyaf before his death in an American raid last year, and had sent the terrorist group tens of millions of dollars in oil and gas revenue generated from at least five oil fields he controlled in Al Barakah, Syria.

Mr. Juaythini “was the link” between Mr. Baghdadi and armed groups in Gaza, the department said, and the No. 2 leader of the Mujahidin Shura Council, another sanctioned group that the United States government considers a terrorist organization. The Treasury Department said Mr. Juaythini had tried in 2013 to obtain money and supplies to help that group conduct attacks against Israel. More recently, he “was instrumental in fostering connections between Gaza- and Libya-based terrorists, and facilitating their travel to Syria,” the department said.

Mr. Binali, appointed as the Islamic State’s chief religious adviser in 2014, has acted as a recruiter for the group, and in June 2015, the department said he announced on social media that its next attack would be in Bahrain. Bahrain had revoked his citizenship a few months earlier.